﻿using EulerLib;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Problem11
{
    class Program
    {
        static int[][] grid = new int[][]{
            new int[]{08, 02, 22, 97, 38, 15, 00, 40, 00, 75, 04, 05, 07, 78, 52, 12, 50, 77, 91, 08},
            new int[]{49, 49, 99, 40, 17, 81, 18, 57, 60, 87, 17, 40, 98, 43, 69, 48, 04, 56, 62, 00},
            new int[]{81, 49, 31, 73, 55, 79, 14, 29, 93, 71, 40, 67, 53, 88, 30, 03, 49, 13, 36, 65},
            new int[]{52, 70, 95, 23, 04, 60, 11, 42, 69, 24, 68, 56, 01, 32, 56, 71, 37, 02, 36, 91},
            new int[]{22, 31, 16, 71, 51, 67, 63, 89, 41, 92, 36, 54, 22, 40, 40, 28, 66, 33, 13, 80},
            new int[]{24, 47, 32, 60, 99, 03, 45, 02, 44, 75, 33, 53, 78, 36, 84, 20, 35, 17, 12, 50},
            new int[]{32, 98, 81, 28, 64, 23, 67, 10, 26, 38, 40, 67, 59, 54, 70, 66, 18, 38, 64, 70},
            new int[]{67, 26, 20, 68, 02, 62, 12, 20, 95, 63, 94, 39, 63, 08, 40, 91, 66, 49, 94, 21},
            new int[]{24, 55, 58, 05, 66, 73, 99, 26, 97, 17, 78, 78, 96, 83, 14, 88, 34, 89, 63, 72},
            new int[]{21, 36, 23, 09, 75, 00, 76, 44, 20, 45, 35, 14, 00, 61, 33, 97, 34, 31, 33, 95},
            new int[]{78, 17, 53, 28, 22, 75, 31, 67, 15, 94, 03, 80, 04, 62, 16, 14, 09, 53, 56, 92},
            new int[]{16, 39, 05, 42, 96, 35, 31, 47, 55, 58, 88, 24, 00, 17, 54, 24, 36, 29, 85, 57},
            new int[]{86, 56, 00, 48, 35, 71, 89, 07, 05, 44, 44, 37, 44, 60, 21, 58, 51, 54, 17, 58},
            new int[]{19, 80, 81, 68, 05, 94, 47, 69, 28, 73, 92, 13, 86, 52, 17, 77, 04, 89, 55, 40},
            new int[]{04, 52, 08, 83, 97, 35, 99, 16, 07, 97, 57, 32, 16, 26, 26, 79, 33, 27, 98, 66},
            new int[]{88, 36, 68, 87, 57, 62, 20, 72, 03, 46, 33, 67, 46, 55, 12, 32, 63, 93, 53, 69},
            new int[]{04, 42, 16, 73, 38, 25, 39, 11, 24, 94, 72, 18, 08, 46, 29, 32, 40, 62, 76, 36},
            new int[]{20, 69, 36, 41, 72, 30, 23, 88, 34, 62, 99, 69, 82, 67, 59, 85, 74, 04, 36, 16},
            new int[]{20, 73, 35, 29, 78, 31, 90, 01, 74, 31, 49, 71, 48, 86, 81, 16, 23, 57, 05, 54},
            new int[]{01, 70, 54, 71, 83, 51, 54, 69, 16, 92, 33, 48, 61, 43, 52, 01, 89, 19, 67, 48}
        };

        static void Main(string[] args)
        {
            Point topLeft = new Point() { X = 0, Y = 0 };
            Point bottomRight = new Point() { X = 19, Y = 19 };
            Grid gridBoundaries = new Grid() { TopLeft = topLeft, BottomRight = bottomRight };
            long max = 0;
            var allDirections = Enum.GetValues(typeof(Direction));
            
            for (int i = 0; i < 20; i++)
            {
                for (int j = 0; j < 20; j++)
                {
                    Point activePoint = new Point();
                    activePoint.X = i;
                    activePoint.Y = j;

                    foreach(Direction direction in allDirections)
                    {
                        List<Point> allPoints = new List<Point>(4);
                        allPoints.Add(activePoint);
                        allPoints.AddRange(activePoint.GetPointsInDirection(direction, 3));

                        long mult = GetMultiplication(allPoints, grid, gridBoundaries);

                        if (mult > max)
                        {
                            max = mult;
                        }
                    }
                }
            }

            Console.WriteLine(max);
            Console.ReadKey();
        }

        private static long GetMultiplication(List<Point> allPoints, int[][] grid, Grid gridBoundaries)
        {
            long val = 1;

            foreach (Point p in allPoints)
            {
                if (!gridBoundaries.WithinBoundaries(p))
                {
                    return -1;
                }

                val *= grid[p.X][p.Y];
            }

            return val;
        }
    }
}
